Report_GeotechEarthSolutionsNWLLC
EarthSolutions
NW LLC
15365 N.E.90th Street,Suite 100 Redmond,WA 98052
(425)449-4704 Fax (425)449-4711
www.earthsolutionsnw.com
Geotechnical Engineering
Construction Observation/Testing
Environmental Services
GEOTECHNICAL ENGINEERING STUDY
CRYSTAL SPRINGS
714 CRYSTAL SPRINGS STREET NORTHWEST
YELM,WASHINGTON
ES-8113
PREPARED FOR
COPPER RIDGE, LLC
October 6, 2021
_________________________
Scott S. Riegel, L.G., L.E.G.
Senior Project Manager
________________________
Kyle R. Campbell, P.E.
Principal Engineer
GEOTECHNICAL ENGINEERING STUDY
CRYSTAL SPRINGS
714 CRYSTAL SPRINGS STREET NORTHWEST
YELM, WASHINGTON
ES-8113
Earth Solutions NW, LLC
15365 Northeast 90th Street, Suite 100
Redmond, Washington 98052
Phone: 425-449-4704 | Fax: 425-449-4711
www.earthsolutionsnw.com
10/06/2021
Geotechnical-Engineering Report
Important Information about This
Subsurface problems are a principal cause of construction delays, cost overruns, claims, and disputes.
While you cannot eliminate all such risks, you can manage them. The following information is provided to help.
The Geoprofessional Business Association (GBA)
has prepared this advisory to help you – assumedly
a client representative – interpret and apply this
geotechnical-engineering report as effectively as
possible. In that way, you can benefit from a lowered
exposure to problems associated with subsurface
conditions at project sites and development of
them that, for decades, have been a principal cause
of construction delays, cost overruns, claims,
and disputes. If you have questions or want more
information about any of the issues discussed herein,
contact your GBA-member geotechnical engineer.
Active engagement in GBA exposes geotechnical
engineers to a wide array of risk-confrontation
techniques that can be of genuine benefit for
everyone involved with a construction project.
Understand the Geotechnical-Engineering Services
Provided for this Report
Geotechnical-engineering services typically include the planning,
collection, interpretation, and analysis of exploratory data from
widely spaced borings and/or test pits. Field data are combined
with results from laboratory tests of soil and rock samples obtained
from field exploration (if applicable), observations made during site
reconnaissance, and historical information to form one or more models
of the expected subsurface conditions beneath the site. Local geology
and alterations of the site surface and subsurface by previous and
proposed construction are also important considerations. Geotechnical
engineers apply their engineering training, experience, and judgment
to adapt the requirements of the prospective project to the subsurface
model(s). Estimates are made of the subsurface conditions that
will likely be exposed during construction as well as the expected
performance of foundations and other structures being planned and/or
affected by construction activities.
The culmination of these geotechnical-engineering services is typically a
geotechnical-engineering report providing the data obtained, a discussion
of the subsurface model(s), the engineering and geologic engineering
assessments and analyses made, and the recommendations developed
to satisfy the given requirements of the project. These reports may be
titled investigations, explorations, studies, assessments, or evaluations.
Regardless of the title used, the geotechnical-engineering report is an
engineering interpretation of the subsurface conditions within the context
of the project and does not represent a close examination, systematic
inquiry, or thorough investigation of all site and subsurface conditions.
Geotechnical-Engineering Services are Performed
for Specific Purposes, Persons, and Projects,
and At Specific Times
Geotechnical engineers structure their services to meet the specific
needs, goals, and risk management preferences of their clients. A
geotechnical-engineering study conducted for a given civil engineer
will not likely meet the needs of a civil-works constructor or even a
different civil engineer. Because each geotechnical-engineering study
is unique, each geotechnical-engineering report is unique, prepared
solely for the client.
Likewise, geotechnical-engineering services are performed for a specific
project and purpose. For example, it is unlikely that a geotechnical-
engineering study for a refrigerated warehouse will be the same as
one prepared for a parking garage; and a few borings drilled during
a preliminary study to evaluate site feasibility will not be adequate to
develop geotechnical design recommendations for the project.
Do not rely on this report if your geotechnical engineer prepared it:
• for a different client;
• for a different project or purpose;
• for a different site (that may or may not include all or a portion of
the original site); or
• before important events occurred at the site or adjacent to it;
e.g., man-made events like construction or environmental
remediation, or natural events like floods, droughts, earthquakes,
or groundwater fluctuations.
Note, too, the reliability of a geotechnical-engineering report can
be affected by the passage of time, because of factors like changed
subsurface conditions; new or modified codes, standards, or
regulations; or new techniques or tools. If you are the least bit uncertain
about the continued reliability of this report, contact your geotechnical
engineer before applying the recommendations in it. A minor amount
of additional testing or analysis after the passage of time – if any is
required at all – could prevent major problems.
Read this Report in Full
Costly problems have occurred because those relying on a geotechnical-
engineering report did not read the report in its entirety. Do not rely on
an executive summary. Do not read selective elements only. Read and
refer to the report in full.
You Need to Inform Your Geotechnical Engineer
About Change
Your geotechnical engineer considered unique, project-specific factors
when developing the scope of study behind this report and developing
the confirmation-dependent recommendations the report conveys.
Typical changes that could erode the reliability of this report include
those that affect:
• the site’s size or shape;
• the elevation, configuration, location, orientation,
function or weight of the proposed structure and
the desired performance criteria;
• the composition of the design team; or
• project ownership.
As a general rule, always inform your geotechnical engineer of project
or site changes – even minor ones – and request an assessment of their
impact. The geotechnical engineer who prepared this report cannot accept
responsibility or liability for problems that arise because the geotechnical
engineer was not informed about developments the engineer otherwise
would have considered.
Most of the “Findings” Related in This Report
Are Professional Opinions
Before construction begins, geotechnical engineers explore a site’s
subsurface using various sampling and testing procedures. Geotechnical
engineers can observe actual subsurface conditions only at those specific
locations where sampling and testing is performed. The data derived from
that sampling and testing were reviewed by your geotechnical engineer,
who then applied professional judgement to form opinions about
subsurface conditions throughout the site. Actual sitewide-subsurface
conditions may differ – maybe significantly – from those indicated in
this report. Confront that risk by retaining your geotechnical engineer
to serve on the design team through project completion to obtain
informed guidance quickly, whenever needed.
This Report’s Recommendations Are
Confirmation-Dependent
The recommendations included in this report – including any options or
alternatives – are confirmation-dependent. In other words, they are not
final, because the geotechnical engineer who developed them relied heavily
on judgement and opinion to do so. Your geotechnical engineer can finalize
the recommendations only after observing actual subsurface conditions
exposed during construction. If through observation your geotechnical
engineer confirms that the conditions assumed to exist actually do exist,
the recommendations can be relied upon, assuming no other changes have
occurred. The geotechnical engineer who prepared this report cannot assume
responsibility or liability for confirmation-dependent recommendations if you
fail to retain that engineer to perform construction observation.
This Report Could Be Misinterpreted
Other design professionals’ misinterpretation of geotechnical-
engineering reports has resulted in costly problems. Confront that risk
by having your geotechnical engineer serve as a continuing member of
the design team, to:
• confer with other design-team members;
• help develop specifications;
• review pertinent elements of other design professionals’ plans and
specifications; and
• be available whenever geotechnical-engineering guidance is needed.
You should also confront the risk of constructors misinterpreting this
report. Do so by retaining your geotechnical engineer to participate in
prebid and preconstruction conferences and to perform construction-
phase observations.
Give Constructors a Complete Report and Guidance
Some owners and design professionals mistakenly believe they can shift
unanticipated-subsurface-conditions liability to constructors by limiting
the information they provide for bid preparation. To help prevent
the costly, contentious problems this practice has caused, include the
complete geotechnical-engineering report, along with any attachments
or appendices, with your contract documents, but be certain to note
conspicuously that you’ve included the material for information purposes
only. To avoid misunderstanding, you may also want to note that
“informational purposes” means constructors have no right to rely on
the interpretations, opinions, conclusions, or recommendations in the
report. Be certain that constructors know they may learn about specific
project requirements, including options selected from the report, only
from the design drawings and specifications. Remind constructors
that they may perform their own studies if they want to, and be sure to
allow enough time to permit them to do so. Only then might you be in
a position to give constructors the information available to you, while
requiring them to at least share some of the financial responsibilities
stemming from unanticipated conditions. Conducting prebid and
preconstruction conferences can also be valuable in this respect.
Read Responsibility Provisions Closely
Some client representatives, design professionals, and constructors do
not realize that geotechnical engineering is far less exact than other
engineering disciplines. This happens in part because soil and rock on
project sites are typically heterogeneous and not manufactured materials
with well-defined engineering properties like steel and concrete. That
lack of understanding has nurtured unrealistic expectations that have
resulted in disappointments, delays, cost overruns, claims, and disputes.
To confront that risk, geotechnical engineers commonly include
explanatory provisions in their reports. Sometimes labeled “limitations,”
many of these provisions indicate where geotechnical engineers’
responsibilities begin and end, to help others recognize their own
responsibilities and risks. Read these provisions closely. Ask questions.
Your geotechnical engineer should respond fully and frankly.
Geoenvironmental Concerns Are Not Covered
The personnel, equipment, and techniques used to perform an
environmental study – e.g., a “phase-one” or “phase-two” environmental
site assessment – differ significantly from those used to perform a
geotechnical-engineering study. For that reason, a geotechnical-engineering
report does not usually provide environmental findings, conclusions, or
recommendations; e.g., about the likelihood of encountering underground
storage tanks or regulated contaminants. Unanticipated subsurface
environmental problems have led to project failures. If you have not
obtained your own environmental information about the project site,
ask your geotechnical consultant for a recommendation on how to find
environmental risk-management guidance.
Obtain Professional Assistance to Deal with
Moisture Infiltration and Mold
While your geotechnical engineer may have addressed groundwater,
water infiltration, or similar issues in this report, the engineer’s
services were not designed, conducted, or intended to prevent
migration of moisture – including water vapor – from the soil
through building slabs and walls and into the building interior, where
it can cause mold growth and material-performance deficiencies.
Accordingly, proper implementation of the geotechnical engineer’s
recommendations will not of itself be sufficient to prevent
moisture infiltration. Confront the risk of moisture infiltration by
including building-envelope or mold specialists on the design team.
Geotechnical engineers are not building-envelope or mold specialists.
Copyright 2019 by Geoprofessional Business Association (GBA). Duplication, reproduction, or copying of this document, in whole or in part, by any means whatsoever, is strictly
prohibited, except with GBA’s specific written permission. Excerpting, quoting, or otherwise extracting wording from this document is permitted only with the express written permission of
GBA, and only for purposes of scholarly research or book review. Only members of GBA may use this document or its wording as a complement to or as an element of a report of any kind.
Any other firm, individual, or other entity that so uses this document without being a GBA member could be committing negligent or intentional (fraudulent) misrepresentation.
Telephone: 301/565-2733
e-mail: info@geoprofessional.org www.geoprofessional.org
October 6, 2021
ES-8113
Copper Ridge, LLC
P.O. Box 73790
Puyallup, Washington 98373
Attention: Mr. Evan Mann
Dear Mr. Mann:
Earth Solutions NW, LLC (ESNW) is pleased to present this report supporting the planned
residential development for Yelm, Washington. In our opinion, the proposed residential
development is feasible from a geotechnical standpoint. Based on the conditions observed
during our fieldwork, the subject site is underlain primarily by recessional outwash deposits that
are suitable for infiltration. The proposed structures can be supported on conventional spread
and continuous foundations bearing on competent native soil, recompacted native soil, or new
structural fill placed directly on competent native soil. In general, competent native soil suitable
for support of foundations will likely be encountered at depths of about two to four feet below the
existing ground surface (bgs). Where loose or unsuitable soil conditions are exposed at
foundation subgrade elevations, compaction of soils to the specifications of structural fill, or
overexcavation and replacement with suitable structural fill, will likely be necessary.
This report provides recommendations for foundation subgrade preparation, foundation and
retaining wall design parameters, drainage, infiltration recommendations, the suitability of the on-
site soils for use as structural fill, and other geotechnical recommendations.
The opportunity to be of service to you is appreciated. If you have any questions regarding the
content of this geotechnical engineering study, please call.
Sincerely,
EARTH SOLUTIONS NW, LLC
Scott S. Riegel, L.G., L.E.G.
Senior Project Manager
15365 N.E. 90th Street, Suite 100 • Redmond, WA 98052 •(425) 449-4704 • FAX (425) 449-4711
Earth Solutions NW LLC
Geotechnical Engineering, Construction
Observation/Testing and Environmental Services
Earth Solutions NW, LLC
Table of Contents
ES-8113
PAGE
INTRODUCTION ................................................................................. 1
General..................................................................................... 1
Project Description ................................................................. 1
SITE CONDITIONS ............................................................................. 2
Surface ..................................................................................... 2
Subsurface .............................................................................. 2
Topsoil and Fill ............................................................. 2
Native Soil ..................................................................... 3
Geologic Setting ........................................................... 3
Groundwater ................................................................. 3
Geologically Hazardous Areas .............................................. 3
DISCUSSION AND RECOMMENDATIONS ....................................... 3
General..................................................................................... 3
Site Preparation and Earthwork ............................................. 4
Temporary Erosion Control ......................................... 4
In-Situ Soils .................................................................. 4
Wet Season Grading .................................................... 4
Structural Fill ................................................................ 4
Excavations and Slopes .............................................. 5
Foundations ............................................................................ 5
Seismic Design Considerations ............................................ 6
Slab-on-Grade Floors ............................................................. 7
Retaining Walls ....................................................................... 7
Drainage................................................................................... 8
Infiltration Evaluation ................................................... 8
Test Method .................................................................. 8
Test Results .................................................................. 9
Soil Types and Site Variability .................................... 9
Restrictive Layer .......................................................... 9
Summary and Recommendations............................... 9
Utility Support and Trench Backfill ....................................... 10
Pavement Sections ................................................................. 10
LIMITATIONS ...................................................................................... 11
Additional Services ................................................................. 11
Earth Solutions NW, LLC
Table of Contents
Cont’d
ES-8113
GRAPHICS
Plate 1 Vicinity Map
Plate 2 Test Pit Location Plan
Plate 3 Retaining Wall Drainage Detail
Plate 4 Footing Drain Detail
APPENDICES
Appendix A Subsurface Exploration
Test Pit Logs
Appendix B Laboratory Test Results
Earth Solutions NW, LLC
GEOTECHNICAL ENGINEERING STUDY
CRYSTAL SPRINGS
714 CRYSTAL SPRINGS STREET NORTHWEST
YELM, WASHINGTON
ES-8113
INTRODUCTION
General
This report was prepared for the proposed residential development to be constructed at 714
Crystal Springs Street Northwest in Yelm, Washington. The purpose of this study was to provide
geotechnical recommendations for the proposed development. Our scope of services for
completing this geotechnical engineering study included the following:
Observing, logging, and sampling test pits for purposes of characterizing site soil and
groundwater conditions;
Laboratory testing of soil samples collected at the test pit locations;
Engineering analyses and recommendations for the proposed development, and;
Preparation of this report.
The following documents and resources were reviewed as part of our report preparation:
Geologic Map of the Centralia Quadrangle, Washington, 1987;
Conceptual Site Plan, undated;
Web Soil Survey (WSS) online resource, maintained by the Natural Resources
Conservation Service under the United States Department of Agriculture, and;
Yelm Municipal Code Title 18.21: Critical Areas and Resource Lands.
Project Description
Based on review of the referenced plans, the subject site will be redeveloped with up to 30 single-
family residences and associated improvements. Grading plans were not available at the time
this report was prepared; however, given the low topographic relief on this site, we anticipate
grading may include cuts and fills of up to about five feet with deeper excavations required to
install underground utilities.
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At the time this report was prepared, specific building load values were not available; however,
we anticipate the proposed residential structures will consist of relatively lightly loaded wood
framing supported on conventional foundations. Based on our experience with similar
developments, we estimate wall loads on the order of 1 to 2 kips per linear foot and slab-on-grade
loading of 150 pounds per square foot (psf). The feasibility of infiltrating runoff into native soils is
being investigated as part of the project plans.
If the above design assumptions are incorrect or change, ESNW should be contacted to review
the recommendations in this report. ESNW should review the final design to verify the
geotechnical recommendations provided in this report have been incorporated into the plans.
SITE CONDITIONS
Surface
The subject site is located east of Crystal Springs Street Northwest in Yelm, Washington, as
illustrated on the Vicinity Map (Plate 1). The site consists of a single tax parcel (Thurston County
Parcel Number 22719210403) currently developed with a single-family residence, barn, detached
garage, and associated improvements. The majority of the subject site is lightly to moderately
vegetated with tall grass, and sparse trees and general landscaping around existing buildings.
Topography is relatively level, with less than about five feet of total elevation change across the
site.
Subsurface
A representative of ESNW observed, logged, and sampled six test pits, excavated at accessible
locations within the proposed development area, on August 31, 2021, using a trackhoe and
operator provided by the client. The approximate locations of the test pits are depicted on Plate
2 (Test Pit Location Plan). Please refer to the test pit logs provided in Appendix A for a more
detailed description of subsurface conditions. Representative soil samples collected at the test
pit locations were analyzed in general accordance with Unified Soil Classification System (USCS)
and United States Department of Agriculture (USDA) methods and procedures.
Topsoil and Fill
Topsoil was observed extending to depths of approximately 6 to 12 inches below existing grades.
The topsoil thickness is variable and vegetation roots often extend below the topsoil zone into
the underlying weathered native soil. The topsoil was characterized by dark brown color and fine
organic material. Topsoil is not suitable for use as structural fill nor should it be mixed with
material to be used as structural fill. Topsoil or otherwise unsuitable material can be used in
landscape areas if desired.
Fill was not encountered within the test pits; however, fill is likely present near the existing
structures to some degree. If fill is encountered during construction, ESNW should be consulted
to verify the suitability for support of the proposed structures and/or reuse as structural fill.
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Native Soil
Underlying the topsoil, native soils consisted primarily of medium dense to dense poorly and well-
graded gravel with variable sand (USCS: GP and GW respectively). The native soils were
generally encountered in a damp to moist condition and extended to the maximum exploration
depth of 13 feet below ground surface (bgs). We encountered scattered large cobbles and small
boulders at the test pit locations.
Geologic Setting
The referenced geologic map resource identifies recessional outwash, specifically Vashon drift
gravel (Qdvg), across the site and surrounding areas. The referenced WSS resource identifies
Spanaway gravelly sandy loam (Map Unit Symbols: 110 and 111) across the site and surrounding
areas. Spanaway gravelly loam was formed in outwash plains. Based on our field observations,
native soils on site are generally consistent with the geologic setting outlined in this section.
Groundwater
Groundwater was not encountered, at the time of our exploration (August 31, 2021).
Groundwater seepage rates and elevations fluctuate depending on many factors, including
precipitation duration and intensity, the time of year, and soil conditions. In general, groundwater
flow rates are higher during the wetter, winter, spring, and early summer months.
Geologically Hazardous Areas
As part of this report, the subject property was evaluated for the presence of geologically
hazardous areas in general accordance with the applicable Yelm municipal code. Based on our
investigation, the site does not lie within or is immediately adjacent to geologically hazardous
areas.
DISCUSSION AND RECOMMENDATIONS
General
In our opinion, the proposed residential structures can be supported on conventional spread and
continuous foundations bearing on undisturbed competent native soil, recompacted native soil or
new structural fill placed directly on competent native soil. Competent soils suitable for support
of foundations are anticipated to be exposed at depths of about two to four feet below existing
grades across the majority of the site. Slab-on-grade floors should be supported on competent
native soil, re-compacted native soil, or new structural fill. Organic material exposed at subgrade
elevations must be removed below design elevation and grades restored with structural fill.
Where loose, organic or other unsuitable materials are encountered at or below the footing
subgrade elevation, the material should be removed and replaced with structural fill, as
necessary.
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This study has been prepared for the exclusive use of Copper Ridge, LLC and their
representatives. No warranty, expressed or implied, is made. This study has been prepared in
a manner consistent with the level of care and skill ordinarily exercised by other members of the
profession currently practicing under similar conditions in this area.
Site Preparation and Earthwork
Site preparation activities will consist of installing temporary erosion control measures and
performing clearing and site stripping. Grading activities will likely consist of cuts and fills on the
order five feet with the deeper cuts associated with stormwater facilities and utility excavations.
Temporary Erosion Control
Temporary construction entrances and drive lanes, consisting of at least six inches of quarry
spalls, should be considered in order to minimize off-site soil tracking and to provide a temporary
road surface. Temporary slopes and stockpiles should be covered when not in use. Silt fencing
should be installed along the margins of the property. Temporary infiltration swales and galleries
can be considered for control of stormwater. Erosion control measures should conform to the
applicable Washington State Department of Ecology and City of Yelm/Thurston County
standards.
In-Situ Soils
The majority of the soils encountered during our subsurface exploration have a low to moderate
sensitivity to moisture and were generally in a damp to moist condition at the time of the
exploration on August 2021. Soils encountered during site excavations that are excessively over
the optimum moisture content will require aeration or treatment prior to placement and
compaction. Conversely, soils that are substantially below the optimum moisture content will
require moisture conditioning through the addition of water prior to use as structural fill. An ESNW
representative should determine the suitability of in-situ soils for use as structural fill at the time
of construction.
Wet Season Grading
If grading takes place during the wet season surface water could collect and degrade site soils if
not property controlled. The contractor should establish temporary drainage control measures,
such as swales and ponds, prior to extended wet weather. ESNW should be consulted during
construction to provide temporary drainage control recommendations.
Structural Fill
Structural fill is defined as compacted soil placed in foundation, slab-on-grade, and roadway
areas. Fills placed to construct permanent slopes and throughout retaining wall and utility trench
backfill areas are considered structural fill as well. Soils placed in structural areas should be
placed in loose lifts of 12 inches or less and compacted to a relative compaction of 95 percent,
based on the laboratory maximum dry density as determined by the Modified Proctor Method
(ASTM D1557). More stringent compaction specifications may be required for utility trench
backfill zones depending on the responsible utility district or jurisdiction.
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Excavations and Slopes
The Federal Occupation Safety and Health Administration (OSHA) and the Washington Industrial
Safety and Health Act (WISHA) provide soil classification in terms of temporary slope inclinations.
Soils that exhibit a high compressive strength are allowed steeper temporary slope inclinations
than are soils that exhibit lower strength characteristics.
Based on the soil conditions encountered at the test pit locations, site soils are classified as Type
C by OSHA. New fill should also be considered Type C soil. Temporary slopes over four feet in
height in Type C soils must be sloped no steeper than (1.5H:1V). Steeper temporary slopes may
be feasible and should be evaluated by ESNW during construction. Where encountered, the
presence of groundwater seepage may cause caving of temporary slopes. ESNW should
observe site excavations to confirm soil types and allowable slope inclinations. If the
recommended temporary slope inclinations cannot be achieved, temporary shoring may be
necessary to support excavations, particularly utility trench excavations.
Permanent slopes should be planted with vegetation to enhance stability and to minimize erosion
and should maintain a gradient of 2H:1V or flatter. An ESNW representative should observe
temporary and permanent slopes to confirm the slope inclinations are suitable for the exposed
soil conditions. Supplementary recommendations with respect to excavations and slopes may
be provided as conditions warrant.
Foundations
The proposed residential structures can be supported on conventional spread and continuous
footings bearing on undisturbed competent native soil, recompacted native soil, or new structural
fill placed directly on competent native soil. Based on the soil conditions encountered at the test
sites, competent soils suitable for support of foundations are anticipated to be exposed at depths
of about two to four feet below existing grades across the majority of the site. Where loose or
unsuitable soil conditions are observed at foundation subgrade elevations, compaction of the
soils to the specifications of structural fill, or overexcavation and replacement with granular
structural fill will be necessary. Organic material exposed at foundation subgrade elevations must
be removed and grades restored with structural fill.
Provided the structures will be supported as described above, the following parameters can be
used for design of the new foundations:
Allowable soil bearing capacity 2,500 psf
Passive earth pressure 300 pcf (equivalent fluid)
Coefficient of friction 0.40
A one-third increase in the allowable soil bearing capacity can be assumed for short-term wind
and seismic loading conditions.
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With structural loading as expected, total settlement in the range of 1.0 inch is anticipated, with
differential settlement of about 0.5 inch. The majority of the settlements should occur during
construction, as dead loads are applied.
Seismic Design Considerations
The 2018 International Building Code (2018 IBC) recognizes the most recent edition of the
Minimum Design Loads for Buildings and Other Structures manual (ASCE 7-16) for seismic
design, specifically with respect to earthquake loads. Based on the soil conditions encountered
at the test pit locations, the parameters and values provided below are recommended for seismic
design per the 2018 IBC.
Parameter Value
Site Class D*
Mapped short period spectral response acceleration, S S (g) 1.291
Mapped 1-second period spectral response acceleration, S 1 (g) 0.466
Short period site coefficient, Fa 1
Long period site coefficient, Fv 1.88†
Adjusted short period spectral response acceleration, S MS (g) 1.291
Adjusted 1-second period spectral response acceleration, S M1 (g) 0.876†
Design short period spectral response acceleration, S DS (g) 0.861
Design 1-second period spectral response acceleration, S D1 (g) 0.584†
* Assumes medium dense native soil conditions, encountered to a maximum depth of 13 feet bgs during the August
2021 field exploration, remain medium dense or better to at least 100 feet bgs.
† Values assume Fv may be determined using linear interpolation per Table 11.4-2 in ASCE 7-16.
As indicated in the table footnote, several of the seismic design values provided above are
dependent on the assumption that site-specific ground motion analysis (per Section 11.4.8 of
ASCE 7-16) will not be required for the subject project. ESNW recommends the validity of this
assumption be confirmed at the earliest available opportunity during the planning and early
design stages of the project. Further discussion between the project structural engineer, the
project owner, and ESNW may be prudent to determine the possible impacts to the structural
design due to increased earthquake load requirements under the 2018 IBC. ESNW can provide
additional consulting services to aid with design efforts, including supplementary geotechnical
and geophysical investigation, upon request.
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Liquefaction is a phenomenon where saturated or loose soil suddenly loses internal strength and
behaves as a fluid. This behavior is in response to increased pore water pressures resulting from
an earthquake or another intense ground shaking. In our opinion, site susceptibility to liquefaction
may be considered low. The depth of the local groundwater table and the gradation and relatively
dense characteristics of the native soil were the primary bases for this opinion.
Slab-on-Grade Floors
Slab-on-grade floors for the proposed residential structures should be supported on a firm and
unyielding subgrade. Unstable or yielding areas of the subgrade should be recompacted, or
overexcavated and replaced with suitable structural fill, prior to construction of the slab.
A capillary break consisting of a minimum of four inches of free-draining crushed rock or gravel
should be placed below the slab. The free-draining material should have a fines content of 5
percent or less (percent passing the Number 200 sieve, based on the minus three-quarter-inch
fraction). In areas where slab moisture is undesirable, installation of a vapor barrier below the
slab should be considered. If a vapor barrier is to be utilized, it should be a material specifically
designed for use as a vapor barrier and should be installed in accordance with the specifications
of the manufacturer.
Retaining Walls
Retaining walls must be designed to resist earth pressures and applicable surcharge loads. The
following parameters can be used for retaining wall design:
Active earth pressure (unrestrained condition) 35 pcf
At-rest earth pressure (restrained condition) 55 pcf
Traffic surcharge (passenger vehicles) 70 psf (rectangular distribution)
Passive earth pressure 300 pcf
Coefficient of friction 0.40
Seismic surcharge 8H*
* Where H equals the retained height.
Additional surcharge loading from adjacent foundations, sloped backfill, retaining walls, or other
loads should be included in the retaining wall design. Drainage should be provided behind
retaining walls such that hydrostatic pressures do not develop. If drainage is not provided,
hydrostatic pressures should be included in the wall design.
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October 6, 2021 Page 8
Earth Solutions NW, LLC
Retaining walls should be backfilled with at least 18 inches of free-draining material or suitable
sheet drainage that extends along the height of the wall. The upper one foot of the wall backfill
can consist of a less permeable soil, if desired. A perforated drain pipe should be placed along
the base of the wall and connected to an approved discharge location. A typical retaining wall
drainage detail is provided on Plate 3.
Drainage
Based on our field observations, the native soils generally consisted of well-drained, poorly to
well-graded gravels with slightly variable sand contents. Because of the generally well-drained
nature of the native gravels, significant groundwater is not anticipated to be encountered within
shallow site excavations. ESNW should be consulted during preliminary grading to identify areas
of seepage (if present) and provide recommendations to reduce the potential for instability related
to seepage effects.
Finish grades must be designed to direct surface drain water away from structures and slopes.
The grade adjacent to buildings should be sloped away from the buildings at a gradient of at least
2 percent for a horizontal distance of at least 10 feet or more as setbacks allow. Water must not
be allowed to pond adjacent to structures or slopes. Based on our field observations, it may be
feasible to eliminate foundation drains, provided clean, well-drained deposits are exposed at
footing subgrade elevation. However, confirmation should be provided by ESNW at the time of
construction. A typical foundation drain detail is provided on Plate 4.
Infiltration Evaluation
We conducted in-situ pilot infiltration tests (PITs) at the two areas proposed for infiltration within
the overall development. The PITs were completed at test pit locations TP-1 and TP-4 within
native soils about 8 to 10 feet below existing grades. As indicated in the Subsurface section of
this report, native soils encountered during our fieldwork were characterized primarily as
Spanaway gravels with variable sand content. Based upon the results of USDA textural analyses
performed on representative soil samples, native soils may also be classified chiefly as extremely
gravelly coarse sand. Irrespective of gravel content, fines contents within the native gravels were
generally less than one percent.
Test Method
The bottom of each PIT area was set at the approximate design facility bottom as recommended
in the Method 1 Field Test Methods section of Appendix III-A. Water was metered into each PIT
area using a pump fed hose to develop a constant head of about one foot. The hydraulic head
was maintained until the water truck was emptied (3,800-gallon capacity), and measurements of
flow for each test area was monitored by our field staff. Upon completion of the constant head
soaking period, the water source was removed and each test area was allowed to drain. Upon
drained conditions, the test pits were advanced to the limits of the excavator to determine soil
stratigraphy and check for groundwater.
Copper Ridge, LLC ES-8113
October 6, 2021 Page 9
Earth Solutions NW, LLC
Test Results
Our testing yielded measured (unfactored) infiltration rates of between 90 and 180 inches per
hour (iph). The correction factors below were applied to the measured rates.
Correction Factor Value
Test Method 0.5
Geometry 0.9*
Plugging 0.9
* This value is estimated based on typical pond geometry and uses information collected during the testing.
The total correction factor applied to the measured infiltration rates was 0.4. The resulting long-
term (design) infiltration rate is 36 iph. These rates were calculated using the lowest measured
infiltration rate.
Soil Types and Site Variability
We conducted USDA textural analyses of representative soil samples collected at the PIT areas.
On this basis, the majority of the native soil within the proposed areas consist of extremely
gravelly coarse sand. The samples collected at the tested locations indicated consistent soil
types across the site, with low variability.
Restrictive Layer
On this site, the restrictive layer is groundwater, as the alluvial sand and gravel persisted to the
maximum exploration depth at each location. The groundwater was not identified on this site at
the test pit locations during our fieldwork.
Summary and Recommendations
From a geotechnical standpoint, it is our opinion that the native gravels are suitable for infiltration.
The low soil variability consisting of a consistent thick layer of sand and gravel and low fines
contents within the gravels are the basis of this conclusion. Based on the results of our PIT
program, a long-term infiltration rate of 36 iph may be used for the current infiltration trench design
that will expose coarse gravel soils. Successful performance of the infiltration systems requires
that the base of the facility (receptor soils) exposed sandy soils similar to those encountered at
the test depth. The minimum vertical separation and corresponding trench base elevations
detailed in the referenced groundwater summary should be incorporated into facility designs.
ESNW should review final designs to confirm the recommendations provided in this letter report
are incorporated. ESNW should be retained to observe construction of the infiltration facility
areas during grading to confirm conditions are as anticipated. This site is identified as a highly
susceptible critical aquifer recharge area per YMC section 18.21.070 and will require
performance standards within this section to be met as part of the project design.
Copper Ridge, LLC ES-8113
October 6, 2021 Page 10
Earth Solutions NW, LLC
Utility Support and Trench Backfill
In our opinion, the soils observed at the test pit locations are generally suitable for support of
utilities. The native soils observed at the test pit locations are likely suitable for use as structural
backfill in the utility trench excavations. Utility trench backfill should be placed and compacted to
the specifications of structural fill provided in this report, or to the applicable requirements of
presiding jurisdiction. Native sands and gravels used as backfill should be appropriately moisture
conditioned through the addition of water to mitigate the settlement potential.
Native soils proposed for use as utility trench backfill should contain aggregate of six inches in
diameter or less. Caving of the trench sidewalls should be expected and will require temporary
shoring to ensure safety is maintained during utility installation.
Pavement Sections
The performance of site pavements is largely related to the condition of the underlying subgrade.
To ensure adequate pavement performance, the subgrade should be in a firm and unyielding
condition when subjected to proofrolling with a loaded dump truck. Structural fill in pavement
areas should be compacted to the specifications detailed in the Site Preparation and Earthwork
section of this report. It is possible that soft, wet, or otherwise unsuitable subgrade areas may
still exist after base grading activities. Areas of unsuitable or yielding subgrade conditions may
require remedial measures such as overexcavation and replacement with structural fill or thicker
crushed rock sections prior to pavement.
For relatively lightly loaded pavements subjected to automobiles and occasional truck traffic, the
following sections can be considered for preliminary design:
Two inches of hot mix asphalt (HMA) placed over four inches of CRB, or;
Two inches of HMA placed over three inches of asphalt treated base (ATB).
Heavier traffic areas generally require thicker pavement sections depending on site usage,
pavement life expectancy, and site traffic. For preliminary design purposes, the following
pavement sections for occasional truck traffic areas can be considered:
Three inches of HMA placed over six inches of crushed rock base (CRB), or;
Three inches of HMA placed over four-and-one-half inches of ATB.
The HMA, CRB and ATB materials should conform to WSDOT specifications. Thurston
County/City of Yelm minimum pavement requirements may supersede our recommendations and
may require thicker pavement sections.
Copper Ridge, LLC ES-8113
October 6, 2021 Page 11
Earth Solutions NW, LLC
LIMITATIONS
The recommendations and conclusions provided in this geotechnical engineering study are
professional opinions consistent with the level of care and skill that is typical of other members in
the profession currently practicing under similar conditions in this area. A warranty is not
expressed or implied. Variations in the soil and groundwater conditions observed at the test pit
locations may exist and may not become evident until construction. ESNW should reevaluate
the conclusions in this geotechnical engineering study if variations are encountered.
Additional Services
ESNW should have an opportunity to review the final design with respect to the geotechnical
recommendations provided in this report. ESNW should also be retained to provide testing and
consultation services during construction.
Drwn.MRS
Checked SKH Date Sept.2021
Date 09/20/2021 Proj.No.8113
Plate 1
Earth Solutions NWLLC
Geotechnical Engineering,Construction
EarthSolutionsNWLLC
EarthSolutions
NW LLC Observation/Testing and Environmental Services
Vicinity Map
Crystal Springs
Yelm,Washington
Reference:
Thurston County,Washington
OpenStreetMap.org
NORTH
NOTE:This plate may contain areas of color.ESNW cannot be
responsible for any subsequent misinterpretation of the information
resulting from black &white reproductions of this plate.
Yelm
SITE
Plate
Proj.No.
Date
Checked By
Drwn.ByEarthSolutionsNWLLCGeotechnicalEngineering,ConstructionObservation/TestingandEnvironmentalServicesEarthSolutionsNWLLCEarthSolutionsNWLLCMRS
SKH
09/20/2021
8113
2TestPitLocationPlan CrystalSpringsYelm,WashingtonLEGEND
Approximate Location of
ESNW Test Pit,Proj.No.
ES-8113,Aug.2021
Subject Site
Existing Building
NORTH
0 75 150
Sc ale in Feet1"=150'
NOTE:This plate may contain areas of color.ESNW cannot be
responsible for any subsequent misinterpretation of the information
resulting from black &white reproductions of this plate.
NOTE:The graphics shown on this plate are not intended for design
purposes or precise scale measurements,but only to illustrate the
approximate test locations relative to the approximate locations of
existing and /or proposed site features.The information illustrated
is largely based on data provided by the client at the time of our
study.ESNW cannot be responsible for subsequent design changes
or interpretation of the data by others.
TP-1
95TH C
OURT S.E.W OODLANDCOURT S.E.TP-1
TP-2
TP-3
TP-4
TP-5
TP-6
330
334
330
334
N.W.RHOTONROADN.W.CRYSTALSPRINGSSTREET
Geotechnical Engineering,Construction
Observation/Testing and Environmental Services
Drwn.CAM
Checked SSR Date Oct.2021
Date 10/06/2021 Proj.No.8113
Plate 3
Earth Solutions NWLLCEarthSolutionsNWLLC
EarthSolutions
NW LLC
NOTES:
Free-draining Backfill should consist
of soil having less than 5 percent fines.
Percent passing No.4 sieve should be
25 to 75 percent.
Sheet Drain may be feasible in lieu
of Free-draining Backfill,per ESNW
recommendations.
Drain Pipe should consist of perforated,
rigid PVC Pipe surrounded with 1-inch
Drain Rock.
LEGEND:
Free-draining Structural Backfill
1-inch Drain Rock
18"Min.
Structural
Fill
Perforated Rigid Drain Pipe
(Surround in Drain Rock)
SCHEMATIC ONLY -NOT TO SCALE
NOT A CONSTRUCTION DRAW ING
Retaining Wall Drainage Detail
Crystal Springs
Yelm,Washington
Geotechnical Engineering,Construction
Observation/Testing and Environmental Services
Drwn.CAM
Checked SSR Date Oct.2021
Date 10/06/2021 Proj.No.8113
Plate 4
Earth Solutions NWLLCEarthSolutionsNWLLC
EarthSolutions
NW LLC
Slope
Perforated Rigid Drain Pipe
(Surround in Drain Rock)
18"Min.
NOTES:
Do NOT tie roof downspouts
to Footing Drain.
Surface Seal to consist of
12"of less permeable,suitable
soil.Slope away from building.
LEGEND:
Surface Seal:native soil or
other low-permeability material.
1-inch Drain Rock
SCHEMATIC ONLY -NOT TO SCALE
NOT A CONSTRUCTION DRAW ING
Footing Drain Detail
Crystal Springs
Yelm,Washington
Earth Solutions NW, LLC
Appendix A
Subsurface Exploration
Test Pit Logs
ES-8113
The subsurface conditions at the site were explored by excavating six test pits at the approximate
locations illustrated on Plate 2 of this report. The test pit logs are provided in this Appendix. The
subsurface exploration was completed on August 31, 2021 to a maximum depth of 13 feet below
existing grades.
Logs of the explorations observed by ESNW are presented in Appendix A. The final logs
represent the interpretations of the field logs and the results of laboratory analyses. The
stratification lines on the logs represent the approximate boundaries between soil types. In
actuality, the transitions may be more gradual.
GRAVEL
AND
GRAVELLY
SOILS
CLAYEY GRAVELS, GRAVEL - SAND -
CLAY MIXTURES
WELL-GRADED SANDS, GRAVELLY
SANDS, LITTLE OR NO FINES
POORLY-GRADED SANDS,
GRAVELLY SAND, LITTLE OR NO
FINES
SILTY SANDS, SAND - SILT
MIXTURES
CLAYEY SANDS, SAND - CLAY
MIXTURES
INORGANIC SILTS AND VERY FINE
SANDS, ROCK FLOUR, SILTY OR
CLAYEY FINE SANDS OR CLAYEY
SILTS WITH SLIGHT PLASTICITY
INORGANIC CLAYS OF LOW TO
MEDIUM PLASTICITY, GRAVELLY
CLAYS, SANDY CLAYS, SILTY CLAYS,
LEAN CLAYS
ORGANIC SILTS AND ORGANIC
SILTY CLAYS OF LOW PLASTICITY
INORGANIC SILTS, MICACEOUS OR
DIATOMACEOUS FINE SAND OR
SILTY SOILS
INORGANIC CLAYS OF HIGH
PLASTICITY
SILTS
AND
CLAYS
MORE THAN 50%
OF MATERIAL IS
LARGER THAN
NO. 200 SIEVE
SIZE
MORE THAN 50%
OF MATERIAL IS
SMALLER THAN
NO. 200 SIEVE
SIZE
MORE THAN 50%
OF COARSE
FRACTION
PASSING ON NO.
4 SIEVE
MORE THAN 50%
OF COARSE
FRACTION
RETAINED ON NO.
4 SIEVE
SOIL CLASSIFICATION CHART
(APPRECIABLE
AMOUNT OF FINES)
(APPRECIABLE
AMOUNT OF FINES)
(LITTLE OR NO FINES)
FINE
GRAINED
SOILS
SAND
AND
SANDY
SOILS
SILTS
AND
CLAYS
ORGANIC CLAYS OF MEDIUM TO
HIGH PLASTICITY, ORGANIC SILTS
PEAT, HUMUS, SWAMP SOILS WITH
HIGH ORGANIC CONTENTS
LETTERGRAPH
SYMBOLSMAJOR DIVISIONS
COARSE
GRAINED
SOILS
TYPICAL
DESCRIPTIONS
WELL-GRADED GRAVELS, GRAVEL -
SAND MIXTURES, LITTLE OR NO
FINES
POORLY-GRADED GRAVELS,
GRAVEL - SAND MIXTURES, LITTLE
OR NO FINES
SILTY GRAVELS, GRAVEL - SAND -
SILT MIXTURES
CLEAN
GRAVELS
GRAVELS WITH
FINES
CLEAN SANDS
(LITTLE OR NO FINES)
SANDS WITH
FINES
LIQUID LIMIT
LESS THAN 50
LIQUID LIMIT
GREATER THAN 50
HIGHLY ORGANIC SOILS
DUAL SYMBOLS are used to indicate borderline soil classifications.
The discussion in the text of this report is necessary for a proper understanding of the nature
of the material presented in the attached logs.
GW
GP
GM
GC
SW
SP
SM
SC
ML
CL
OL
MH
CH
OH
PT
Earth Solutions NW LLC
GB
MC = 2.5%
MC = 2.3%
Fines = 1.2%
MC = 3.8%
Fines = 0.3%
TPSL
GP
GP
Dark brown TOPSOIL, abundant roots
Brown poorly graded GRAVEL with sand, medium dense, damp
-abundant cobbles and small boulders present throughout
-minor caving to BOH
[USDA Classification: extremely gravelly coarse SAND]
-infiltration test
Brown poorly graded GRAVEL, dense, damp
[USDA Classification: extremely gravelly coarse SAND]
Test pit terminated at 13.0 feet below existing grade. No groundwater encountered during
excavation. Caving observed from 5.0 to 13.0 feet.
1.0
11.5
13.0
NOTES Depth of Topsoil & Sod 12": field grass
LOGGED BY SKH
EXCAVATION METHOD
EXCAVATION CONTRACTOR Client Provided
CHECKED BY SSR
DATE STARTED 8/31/21 COMPLETED 8/31/21
GROUND WATER LEVEL:
GROUND ELEVATION +-334
LONGITUDE -122.60337 LATITUDE 46.95015
AT TIME OF EXCAVATION
SAMPLE TYPENUMBERDEPTH(ft)0
5
10
PAGE 1 OF 1
TEST PIT NUMBER TP-1
PROJECT NUMBER ES-8113 PROJECT NAME Crystal Springs
GENERAL BH / TP / WELL - 8113.GPJ - GRAPHICS TEMPLATE.GDT - 10/6/21Earth Solutions NW, LLC
15365 N.E. 90th Street, Suite 100
Redmond, Washington 98052
Telephone: 425-449-4704
Fax: 425-449-4711
TESTS
U.S.C.S.MATERIAL DESCRIPTION
GRAPHICLOG
MC = 3.6%
MC = 9.3%
Fines = 0.9%
MC = 3.0%
Fines = 0.4%
TPSL
GP
Dark brown TOPSOIL, abundant roots
Brown poorly graded GRAVEL with sand, medium dense, damp
-abundant cobbles and small boulders present throughout
-minor caving from 3.5' to BOH
-becomes moist
[USDA Classification: extremely gravelly coarse SAND]
-becomes damp
[USDA Classification: extremely gravelly coarse SAND]
Test pit terminated at 11.5 feet below existing grade. No groundwater encountered during
excavation. Caving observed from 3.5 feet to BOH.
1.0
11.5
NOTES Depth of Topsoil & Sod 12": field grass
LOGGED BY SKH
EXCAVATION METHOD
EXCAVATION CONTRACTOR Client Provided
CHECKED BY SSR
DATE STARTED 8/31/21 COMPLETED 8/31/21
GROUND WATER LEVEL:
GROUND ELEVATION +-334
LONGITUDE -122.60344 LATITUDE 46.95049
AT TIME OF EXCAVATION
SAMPLE TYPENUMBERDEPTH(ft)0
5
10
PAGE 1 OF 1
TEST PIT NUMBER TP-2
PROJECT NUMBER ES-8113 PROJECT NAME Crystal Springs
GENERAL BH / TP / WELL - 8113.GPJ - GRAPHICS TEMPLATE.GDT - 10/6/21Earth Solutions NW, LLC
15365 N.E. 90th Street, Suite 100
Redmond, Washington 98052
Telephone: 425-449-4704
Fax: 425-449-4711
TESTS
U.S.C.S.MATERIAL DESCRIPTION
GRAPHICLOG
MC = 1.4%
Fines = 0.4%
MC = 1.8%
Fines = 0.4%
TPSL
GW
GW
Dark brown TOPSOIL, abundant roots
Brown well-graded GRAVEL with sand, medium dense, damp
[USDA Classification: extremely gravelly coarse SAND]
-abundant cobbles and small boulders present throughout
-becomes very dense
-minor caving from 8' to BOH
Brown well-graded GRAVEL, dense, damp
[USDA Classification: extremely gravelly coarse SAND]
Test pit terminated at 11.0 feet below existing grade. No groundwater encountered during
excavation. Caving observed from 8.0 feet to BOH.
1.0
9.0
11.0
NOTES Depth of Topsoil & Sod 12": field grass
LOGGED BY SKH
EXCAVATION METHOD
EXCAVATION CONTRACTOR Client Provided
CHECKED BY SSR
DATE STARTED 8/31/21 COMPLETED 8/31/21
GROUND WATER LEVEL:
GROUND ELEVATION +-333
LONGITUDE -122.60414 LATITUDE 46.95036
AT TIME OF EXCAVATION
SAMPLE TYPENUMBERDEPTH(ft)0
5
10
PAGE 1 OF 1
TEST PIT NUMBER TP-3
PROJECT NUMBER ES-8113 PROJECT NAME Crystal Springs
GENERAL BH / TP / WELL - 8113.GPJ - GRAPHICS TEMPLATE.GDT - 10/6/21Earth Solutions NW, LLC
15365 N.E. 90th Street, Suite 100
Redmond, Washington 98052
Telephone: 425-449-4704
Fax: 425-449-4711
TESTS
U.S.C.S.MATERIAL DESCRIPTION
GRAPHICLOG
MC = 1.8%
MC = 2.1%
Fines = 0.7%
MC = 3.5%
Fines = 0.4%
TPSL
GW
GP
Dark brown TOPSOIL, abundant roots
Brown well-graded GRAVEL with sand, medium dense, damp
-abundant cobbles and small boulders present throughout
-minor caving from 4' to BOH
-infiltration test
[USDA Classification: extremely gravelly coarse SAND]
Brown poorly graded GRAVEL with sand, medium dense, damp
[USDA Classification: extremely gravelly coarse SAND]
Test pit terminated at 11.0 feet below existing grade. No groundwater encountered during
excavation. Caving observed from 4.0 feet to BOH.
1.0
9.5
11.0
NOTES Depth of Topsoil & Sod 12": field grass
LOGGED BY SKH
EXCAVATION METHOD
EXCAVATION CONTRACTOR Client Provided
CHECKED BY SSR
DATE STARTED 8/31/21 COMPLETED 8/31/21
GROUND WATER LEVEL:
GROUND ELEVATION +-331
LONGITUDE -122.60413 LATITUDE 46.95006
AT TIME OF EXCAVATION
SAMPLE TYPENUMBERDEPTH(ft)0
5
10
PAGE 1 OF 1
TEST PIT NUMBER TP-4
PROJECT NUMBER ES-8113 PROJECT NAME Crystal Springs
GENERAL BH / TP / WELL - 8113.GPJ - GRAPHICS TEMPLATE.GDT - 10/6/21Earth Solutions NW, LLC
15365 N.E. 90th Street, Suite 100
Redmond, Washington 98052
Telephone: 425-449-4704
Fax: 425-449-4711
TESTS
U.S.C.S.MATERIAL DESCRIPTION
GRAPHICLOG
MC = 2.4%
MC = 1.7%
Fines = 0.1%
MC = 2.8%
TPSL
GP
Dark brown TOPSOIL, abundant fine roots
Brown poorly graded GRAVEL with sand, dense, damp
-abundant cobbles and small boulders present throughout
-minor caving from 4' to 6'
-minor mottling
-major caving from 6' to BOH
[USDA Classification: extremely gravelly coarse SAND]
Test pit terminated at 10.5 feet below existing grade. No groundwater encountered during
excavation. Caving observed from 4.0 feet to BOH.
0.5
10.5
NOTES Depth of Topsoil & Sod 6": field grass
LOGGED BY SKH
EXCAVATION METHOD
EXCAVATION CONTRACTOR Client Provided
CHECKED BY SSR
DATE STARTED 8/31/21 COMPLETED 8/31/21
GROUND WATER LEVEL:
GROUND ELEVATION +-332
LONGITUDE -122.60331 LATITUDE 46.9495
AT TIME OF EXCAVATION
SAMPLE TYPENUMBERDEPTH(ft)0
5
10
PAGE 1 OF 1
TEST PIT NUMBER TP-5
PROJECT NUMBER ES-8113 PROJECT NAME Crystal Springs
GENERAL BH / TP / WELL - 8113.GPJ - GRAPHICS TEMPLATE.GDT - 10/6/21Earth Solutions NW, LLC
15365 N.E. 90th Street, Suite 100
Redmond, Washington 98052
Telephone: 425-449-4704
Fax: 425-449-4711
TESTS
U.S.C.S.MATERIAL DESCRIPTION
GRAPHICLOG
GB
MC = 2.1%
MC = 2.9%
Fines = 0.7%
MC = 3.8%
TPSL
GP
Dark brown TOPSOIL, abundant fine roots
Brown poorly graded GRAVEL with sand, medium dense, damp
-abundant cobbles and small boulders present throughout
-minor caving from 4.5' to BOH
[USDA Classification: extremely gravelly coarse SAND]
-becomes moist
Test pit terminated at 12.5 feet below existing grade. No groundwater encountered during
excavation. Caving observed from 4.5 feet to BOH.
1.0
12.5
NOTES Depth of Topsoil & Sod 12": field grass
LOGGED BY SKH
EXCAVATION METHOD
EXCAVATION CONTRACTOR Client Provided
CHECKED BY SSR
DATE STARTED 8/31/21 COMPLETED 8/31/21
GROUND WATER LEVEL:
GROUND ELEVATION +-331
LONGITUDE -122.60438 LATITUDE 46.94935
AT TIME OF EXCAVATION
SAMPLE TYPENUMBERDEPTH(ft)0
5
10
PAGE 1 OF 1
TEST PIT NUMBER TP-6
PROJECT NUMBER ES-8113 PROJECT NAME Crystal Springs
GENERAL BH / TP / WELL - 8113.GPJ - GRAPHICS TEMPLATE.GDT - 10/6/21Earth Solutions NW, LLC
15365 N.E. 90th Street, Suite 100
Redmond, Washington 98052
Telephone: 425-449-4704
Fax: 425-449-4711
TESTS
U.S.C.S.MATERIAL DESCRIPTION
GRAPHICLOG
Earth Solutions NW, LLC
Appendix B
Laboratory Test Results
ES-8113
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
0.0010.010.1110100
3
D100
140
Specimen Identification
1
fine
6
HYDROMETER
304
1.2
0.3
0.9
0.4
0.4
101/2
COBBLES
Specimen Identification
4
coarse
20 401.5 8 14
USDA: Brown Extremely Gravelly Coarse Sand. USCS: GP with Sand.
USDA: Brown Extremely Gravelly Coarse Sand. USCS: GP.
USDA: Brown Extremely Gravelly Coarse Sand. USCS: GP with Sand.
USDA: Brown Extremely Gravelly Coarse Sand. USCS: GP with Sand.
USDA: Brown Extremely Gravelly Coarse Sand. USCS: GW with Sand.
6 60
PERCENT FINER BY WEIGHTD10
6.934
12.226
10.116
11.877
7.12
14.952
25.97
27.313
26.824
18.742
GRAIN SIZE DISTRIBUTION
100
18.27
15.34
33.69
22.41
15.61
LL
TP-01
TP-01
TP-02
TP-02
TP-03
0.818
1.693
0.811
1.197
1.2
3/4
U.S. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS
GRAVEL SAND
37.5
75
75
75
37.5
%Silt
3.93
3.40
4.62
4.39
2.25
TP-01
TP-01
TP-02
TP-02
TP-03
2 2003
Cc CuClassification
%Clay
16
PID60 D30
coarse SILT OR CLAYfinemedium
GRAIN SIZE IN MILLIMETERS
3/8 50
7.0ft.
13.0ft.
8.0ft.
11.5ft.
2.0ft.
7.00ft.
13.00ft.
8.00ft.
11.50ft.
2.00ft.
PL
PROJECT NUMBER ES-8113 PROJECT NAME Crystal Springs
GRAIN SIZE USDA ES-8113 CRYSTAL SPRINGS.GPJ GINT US LAB.GDT 9/9/21Earth Solutions NW, LLC
15365 N.E. 90th Street, Suite 100
Redmond, Washington 98052
Telephone: 425-449-4704
Fax: 425-449-4711
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
0.0010.010.1110100
3
D100
140
Specimen Identification
1
fine
6
HYDROMETER
304
0.4
0.7
0.4
0.1
0.7
101/2
COBBLES
Specimen Identification
4
coarse
20 401.5 8 14
USDA: Brown Extremely Gravelly Coarse Sand. USCS: GW.
USDA: Brown Extremely Gravelly Coarse Sand. USCS: GW with Sand.
USDA: Brown Extremely Gravelly Coarse Sand. USCS: GP with Sand.
USDA: Brown Extremely Gravelly Coarse Sand. USCS: GP.
USDA: Brown Extremely Gravelly Coarse Sand. USCS: GP.
6 60
PERCENT FINER BY WEIGHTD10
16.792
7.591
9.26
10.206
15.784
24.998
18.42
21.805
22.982
28.324
GRAIN SIZE DISTRIBUTION
100
5.16
16.56
24.81
4.27
10.23
LL
TP-03
TP-04
TP-04
TP-05
TP-06
4.849
1.112
0.879
5.383
2.768
3/4
U.S. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS
GRAVEL SAND
37.5
37.5
37.5
75
75
%Silt
2.33
2.81
4.47
0.84
3.18
TP-03
TP-04
TP-04
TP-05
TP-06
2 2003
Cc CuClassification
%Clay
16
PID60 D30
coarse SILT OR CLAYfinemedium
GRAIN SIZE IN MILLIMETERS
3/8 50
11.0ft.
8.0ft.
11.0ft.
7.0ft.
7.0ft.
11.00ft.
8.00ft.
11.00ft.
7.00ft.
7.00ft.
PL
PROJECT NUMBER ES-8113 PROJECT NAME Crystal Springs
GRAIN SIZE USDA ES-8113 CRYSTAL SPRINGS.GPJ GINT US LAB.GDT 9/9/21Earth Solutions NW, LLC
15365 N.E. 90th Street, Suite 100
Redmond, Washington 98052
Telephone: 425-449-4704
Fax: 425-449-4711
Earth Solutions NW, LLC
Report Distribution
ES-8113
EMAIL ONLY Copper Ridge, LLC
P.O. Box 73790
Puyallup, Washington 98373
Attention: Mr. Evan Mann